WASHINGTON - Almost three of every four babies born in Coconino County in 2011 were born to unmarried women, the highest rate in the nation, if Census Bureau estimates are correct.
That's a critical question for experts in Arizona, who said the Census estimates have to be treated with caution.
But most experts agreed that births to unmarried women are a problem for Coconino and for Arizona as a whole, which was one of 14 states with rates "significantly higher" than the national average in 2011.
"The overall state percentage is not too surprising," based on teen births, said Sheila Sjolander, assistant director of public health prevention services at the Arizona Department of Health Services. "Arizona has historically had higher rates of teen births than the rest of the country."
The 2013 American Community Survey report said non-marital births made up 39.5 percent of all births in Arizona in 2011, compared to a national rate of 35.7 percent.
It said the rate for the Flagstaff metropolitan area - which includes all of Coconino County - was 74.6 percent that year. By contrast, the Lake Havasu City-Kingman metro area, which covers all of Mohave County, was 10th-lowest in the nation, with just 12.7 percent of babies delivered by unmarried moms in 2011.
But critics of the Census numbers pointed to the large margin of error in the survey: 15.2 percent for the Flagstaff region, which means the number could have been as low as 59.4 percent.
The Arizona Daily Sun reported last year that a review of birth certificates in Coconino County put the actual number of births to unmarried moms at 50 percent in that year - still higher than the state and national rates.
Critics also point to the fact that Native American and Hispanic women nationally had relatively high single-mom birth rates, at 64 percent and 43 percent, respectively. That could have driven up the numbers in Arizona, and particularly in Coconino County, where those two groups account for about 40 percent of the population, they said.
"We've had a lot of issues in Arizona ... with the so-called undocumented immigrants," said Kooros Mahmoudi, a Northern Arizona University sociology professor with expertise in demography.
He said the Census survey could have sampled a fair amount of mothers who "are not going to report the existence of the father," if the father is at risk of deportation.
Tom Rex, an associate director at Arizona State University's W. P. Carey School of Business, said the ACS survey leaves too many questions unanswered and has too large of a margin of error.
"Is (the percentage) high because people aren't getting married but they are still together ... or because there is no man involved?" he asked. "We'd need to know more."
Rex said the report comes from too small a sample to reliably report on smaller categories such as individual states, metro areas, race, age and economic status.
Even if the numbers are spot on, Rex said, their impact does not necessarily mean anything for Arizona because it all depends on who you talk to.
"You can't immediately assume it's the most awful thing in the world," he said. "There are other people who ask, 'What's the big deal?'"
But others said the number of unmarried moms, and the challenges of single parenting, is a big deal. It is an issue that Arizona needs to address, said Chris Coffman, CEO of Helping Hands for Single Moms.
"It is a major factor in our state," Coffman said.
Sjolander said the number of programs in the state that assist single mothers and pregnant teens has increased. Coffman said those programs need to continue to grow with the growing amount of single moms seeking help.
He said the number of people in Arizona applying for assistance like food stamps and low-income housing "are growing, demands are growing, and it's fueled by single parents."